Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done using the HEASARC data.
- 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.48
Process Start Time: Thu Jun 19 22:05:17 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1275005
======================================================================
Trigger: 01275005 Segment: 000
BAT Trigger Time: 756173365.888 [s; MET]
Trigger Stop: 756173378.048 [s; MET]
UTC: 2024-12-18T00:08:51.156520 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 185.682435528346 Dec: 29.9908165521575 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 8.41
Image Trigger?: NO
Rate S/N Ratio: 9.4339811320566 [ if not an image trigger ]
Image S/N Ratio: 8.41
Analysis Position: [ source = BAT ]
RA: 185.682435528346 Dec: 29.9908165521575 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 185.686438643986 Dec: 29.9858745825619 [deg; J2000]
{ 12h 22m 44.7s , +29d 59' 09.1" }
+/- 2.0964173562907 [arcmin] (estimated 90% radius based on SNR)
+/- 0.986700826568091 [arcmin] (formal 1-sigma fit error)
SNR: 10.5648772698192
Angular difference between the analysis and refined position is 0.362216 arcmin
Partial Coding Fraction: 0.5234375 [ including projection effects ]
Duration
T90: 23.3519998788834 +/- 4.45043320850395
Measured from: -0.0839999914169312
to: 23.2679998874664 [s; relative to TRIGTIME]
T50: 11.9639998674393 +/- 4.38963015187202
Measured from: 5.16400003433228
to: 17.1279999017715 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.88800001144409
to: 9.88800001144409 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.82400000095367
to: 26.1599999666214 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.196121 0.269063 0.303078 0.045829
0.044466 0.046821 0.039820 0.032950 [error]
Peak 0.008055 0.040059 0.021920 0.003235
0.008343 0.009331 0.007879 0.006390 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 27.984 -1.824 26.160
T90 23.352 -0.084 23.268
T50 11.964 5.164 17.128
Peak 1.000 8.888 9.888
====== Spectral Analysis Summary =====================================
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^{Ph_index}
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedo
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.319 -0.262 0.267 - - - 2.01e-03 -3.25e-04 3.25e-04 56.110 57
CPL -0.420 -0.984 1.277 95.489 -31.706 -95.489 5.32e-03 -5.32e-03 1.36e-02 53.720 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.250 -0.481 0.525 - - - 5.11e-03 -1.74e-03 1.73e-03 64.120 57
CPL 1.820 -2.634 7.737 63.829 -17.287 76.680 1.62e-01 -1.62e-01 8.65e+02 59.970 56
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence PL 6.06e-08 1.24e-07 2.00e-07 7.14e-07 5.53e-07 1.10e-06 erg/cm2
90%_error_low -1.69e-08 -2.28e-08 -3.81e-08 -2.52e-07 -9.57e-08 -2.85e-07 erg/cm2
90%_error_hi 1.83e-08 2.24e-08 3.76e-08 3.31e-07 9.64e-08 3.48e-07 erg/cm2
Peak flux PL 1.65e-01 1.93e-01 1.63e-01 2.32e-01 6.04e-01 7.53e-01 ph/cm2/s
90%_error_low -8.83e-02 -7.68e-02 -5.86e-02 -1.27e-01 -2.13e-01 -2.55e-01 ph/cm2/s
90%_error_hi 1.06e-01 7.59e-02 5.82e-02 1.91e-01 2.16e-01 2.57e-01 ph/cm2/s
Fluence CPL 5.01e-08 1.34e-07 2.17e-07 2.60e-07 5.31e-07 6.62e-07 erg/cm2
90%_error_low -2.04e-08 -2.63e-08 -4.44e-08 -1.64e-07 -9.86e-08 -1.92e-07 erg/cm2
90%_error_hi 2.16e-08 2.72e-08 4.62e-08 5.55e-07 9.99e-08 5.50e-07 erg/cm2
Peak flux CPL 8.75e-02 2.48e-01 2.08e-01 2.93e-02 5.71e-01 5.73e-01 ph/cm2/s
90%_error_low -8.75e-02 -1.05e-01 -9.02e-02 -2.93e-02 -2.05e-01 -2.07e-01 ph/cm2/s
90%_error_hi 1.18e-01 1.13e-01 8.32e-02 1.34e-01 2.15e-01 2.25e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 185.6864 29.9859 0.0181 35.0314 -141.9895 0.9653575 10.565 TRIG_01275005 Foreground time interval of the image: -1.824 26.160 (delta_t = 27.984 [sec]) Background time interval of the image: -118.387 -1.824 (delta_t = 116.563 [sec])
Light Curves
Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.
Full-time range; 1 s binning
Other quick-look light curves:
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -1.824 sec. to 26.160 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.31928 ( -0.26188 0.267203 ) Norm@50keV : 2.01003E-03 ( -0.000325349 0.00032534 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 56.11 using 59 bins. Reduced chi-squared = 0.984386 # Null hypothesis probability of 5.09e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 27.98 sec: 0.240678 ( -0.040581 0.040772 ) ph/cm2/s Energy fluence (15-150 keV) : 5.53257e-07 ( -9.57078e-08 9.64205e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.824 sec. to 26.160 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.419933 ( -0.983686 1.27725 ) Epeak [keV] : 95.4890 ( -31.6993 -95.4821 ) Norm@50keV : 5.32138E-03 ( -0.00532217 0.0136259 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 53.72 using 59 bins. Reduced chi-squared = 0.959286 # Null hypothesis probability of 5.62e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 27.98 sec: 0.232558 ( -0.041834 0.041882 ) ph/cm2/s Energy fluence (15-150 keV) : 5.31237e-07 ( -9.86354e-08 9.98626e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.888 sec. to 9.888 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.24983 ( -0.483173 0.522468 ) Norm@50keV : 5.10991E-03 ( -0.00173475 0.00172901 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 64.12 using 59 bins. Reduced chi-squared = 1.12491 # Null hypothesis probability of 2.41e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 0.604118 ( -0.212708 0.216064 ) ph/cm2/s Energy fluence (15-150 keV) : 5.11635e-08 ( -1.77232e-08 1.79034e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.888 sec. to 9.888 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: 1.82019 ( -2.78642 7.58462 ) Epeak [keV] : 63.8289 ( -16.3918 77.5755 ) Norm@50keV : 0.161638 ( -0.200615 864.772 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 59.97 using 59 bins. Reduced chi-squared = 1.07089 # Null hypothesis probability of 3.34e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 0.570559 ( -0.204505 0.215094 ) ph/cm2/s Energy fluence (15-150 keV) : 4.52262e-08 ( -1.70955e-08 1.86354e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 23.352 sec. Hardness ratio (energy fluence ratio) = 1.60295027338
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.8511919e-07 S(50-150 keV) = 3.681376e-07
The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.
Mask shadow pattern
IMX = -5.523357671686940E-01, IMY = 4.316954955359277E-01
Spacecraft aspect plot
Bright source in the pre-burst/pre-slew/post-slew images
Pre-burst image of 15-350 keV band
Time interval of the image: -118.387400 -1.824000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.4365 -40.5504 3.5 53.7 5.1 1.5862 3.3 4.2 Vela X-1 116.3987 33.7638 3.1 42.3 117.0 3.3018 3.7 ------ UNKNOWN 141.0115 50.4746 2.6 41.9 154.0 1.7115 4.4 ------ UNKNOWN 179.4252 -38.7922 2.5 54.1 -36.7 4.8443 4.7 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -1.824000 26.160000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.6364 -40.5941 9.1 53.7 4.9 0.3002 1.3 5.5 Vela X-1 134.7620 -41.0358 2.1 54.4 5.5 1.4292 5.3 ------ UNKNOWN 185.6864 29.9859 1.1 35.0 -142.0 0.9653 10.6 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 129.812590 962.223900 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 186.5769 31.8750 2.9 2.0 177.1 4.0289 4.0 ------ UNKNOWN 189.7973 -2.8319 2.5 33.1 -32.2 6.3226 4.7 ------ UNKNOWN